[Fix #1348] Remove dash dependency

1 files changed, 160 insertions, 0 deletions

diff --git a/cider-compat.el b/cider-compat.el
new file mode 100644
index 00000000..d1307336
--- /dev/null
+++ b/cider-compat.el
@@ -0,0 +1,160 @@
+;;; cider-compat.el --- Contributed functions from other projects -*- lexical-binding: t -*-
+
+;; Copyright © 2012-2015 Tim King, Phil Hagelberg
+;; Copyright © 2013-2015 Bozhidar Batsov, Hugo Duncan, Steve Purcell
+;;
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;; This file is not part of GNU Emacs.
+
+;;; Code:
+
+;;; copied from subr-x, as a dash replacement
+
+(eval-and-compile
+
+  (unless (fboundp 'thread-first )
+
+    (defmacro internal--thread-argument (first? &rest forms)
+      "Internal implementation for `thread-first' and `thread-last'.
+When Argument FIRST? is non-nil argument is threaded first, else
+last.  FORMS are the expressions to be threaded."
+      (pcase forms
+        (`(,x (,f . ,args) . ,rest)
+         `(internal--thread-argument
+           ,first? ,(if first? `(,f ,x ,@args) `(,f ,@args ,x)) ,@rest))
+        (`(,x ,f . ,rest) `(internal--thread-argument ,first? (,f ,x) ,@rest))
+        (_ (car forms))))
+
+    (defmacro thread-first (&rest forms)
+      "Thread FORMS elements as the first argument of their successor.
+Example:
+    (thread-first
+      5
+      (+ 20)
+      (/ 25)
+      -
+      (+ 40))
+Is equivalent to:
+    (+ (- (/ (+ 5 20) 25)) 40)
+Note how the single `-' got converted into a list before
+threading."
+      (declare (indent 1)
+               (debug (form &rest [&or symbolp (sexp &rest form)])))
+      `(internal--thread-argument t ,@forms)))
+
+  (unless (fboundp 'thread-last )
+
+    (defmacro thread-last (&rest forms)
+      "Thread FORMS elements as the last argument of their successor.
+Example:
+    (thread-last
+      5
+      (+ 20)
+      (/ 25)
+      -
+      (+ 40))
+Is equivalent to:
+    (+ 40 (- (/ 25 (+ 20 5))))
+Note how the single `-' got converted into a list before
+threading."
+      (declare (indent 1) (debug thread-first))
+      `(internal--thread-argument nil ,@forms))))
+
+
+(eval-and-compile
+
+  (unless (fboundp 'internal--listify)
+
+    (defsubst internal--listify (elt)
+      "Wrap ELT in a list if it is not one."
+      (if (not (listp elt))
+          (list elt)
+        elt)))
+
+  (unless (fboundp 'internal--check-binding)
+
+    (defsubst internal--check-binding (binding)
+      "Check BINDING is properly formed."
+      (when (> (length binding) 2)
+        (signal
+         'error
+         (cons "`let' bindings can have only one value-form" binding)))
+      binding))
+
+  (unless (fboundp 'internal--build-binding-value-form)
+
+    (defsubst internal--build-binding-value-form (binding prev-var)
+      "Build the conditional value form for BINDING using PREV-VAR."
+      `(,(car binding) (and ,prev-var ,(cadr binding)))))
+
+  (unless (fboundp ' internal--build-binding)
+
+    (defun internal--build-binding (binding prev-var)
+      "Check and build a single BINDING with PREV-VAR."
+      (thread-first
+          binding
+        internal--listify
+        internal--check-binding
+        (internal--build-binding-value-form prev-var))))
+
+  (unless (fboundp ' internal--build-bindings)
+
+    (defun internal--build-bindings (bindings)
+      "Check and build conditional value forms for BINDINGS."
+      (let ((prev-var t))
+        (mapcar (lambda (binding)
+                  (let ((binding (internal--build-binding binding prev-var)))
+                    (setq prev-var (car binding))
+                    binding))
+                bindings)))))
+
+(eval-and-compile
+
+  (unless (fboundp 'if-let)
+
+    (defmacro if-let (bindings then &rest else)
+
+      "Process BINDINGS and if all values are non-nil eval THEN, else ELSE.
+Argument BINDINGS is a list of tuples whose car is a symbol to be
+bound and (optionally) used in THEN, and its cadr is a sexp to be
+evalled to set symbol's value.  In the special case you only want
+to bind a single value, BINDINGS can just be a plain tuple."
+      (declare (indent 2)
+               (debug ([&or (&rest (symbolp form)) (symbolp form)] form body)))
+      (when (and (<= (length bindings) 2)
+                 (not (listp (car bindings))))
+        ;; Adjust the single binding case
+        (setq bindings (list bindings)))
+      `(let* ,(internal--build-bindings bindings)
+         (if ,(car (internal--listify (car (last bindings))))
+             ,then
+           ,@else)))
+
+
+    (defmacro when-let (bindings &rest body)
+      "Process BINDINGS and if all values are non-nil eval BODY.
+Argument BINDINGS is a list of tuples whose car is a symbol to be
+bound and (optionally) used in BODY, and its cadr is a sexp to be
+evalled to set symbol's value.  In the special case you only want
+to bind a single value, BINDINGS can just be a plain tuple."
+      (declare (indent 1) (debug if-let))
+      (list 'if-let bindings (macroexp-progn body))))
+
+
+
+  )
+
+(provide 'cider-compat)